TY  - RPRT
TI  - Aerial estimation of the size of gull breeding colonies
AU  - J.A. Kadlec
AU  - W.H. Drury
PY  - 1968
DO  - 10.2307/3798973
UR  - https://pubs.usgs.gov/publication/5220558
ID  - 5220558
ER  -